body{
    background-color: #000;
}

.lunBo{
    overflow: hidden;
    width: 800px;
    height: 420px;
    margin: 250px auto 0;
    background-color: #ccfc;
    border: 10px groove goldenrod;
}

.list{
    transition: .6s;
}

.list li,
.list li img{
    width: 800px;
    height: 420px;
}

.lunBo span{
    display: block;
    top: 0;
    bottom: 0;
    margin: auto;
    width: 40px;
    height: 60px;
    font-size: 3em;
    color: #ccfc;
    cursor: pointer;
    transition: .4s;
    z-index: 10;
}

.lunBo span:hover{
    color: orangered;
    background-color: black;
    opacity: .6;
}

.lunBo span:nth-of-type(1) {
    left: -10px;
}

.lunBo span:nth-of-type(2) {
    right: 0px;
}


